As the biological action of thiol protease such as calpain, papain, cathepsin B, cathepsin H, cathepsin L. etc. has been elucidated, it has been found that the abnormal increase thereof is the cause of various diseases, so that the inhibitors of thiol protease have been used as their therapeutical agents of those diseases. For example,, reports have been issued that calpain inhibitors have effects on animal models with muscular dystrophy, cataract, myocardial infarction, delayed death of neurocytes after brain infarction, and the like, while cathepsin inhibitors have effects on cancer metastasis, amyotrophy, osteoporosis and the like. However, because known inhibitors of thiol proteases, such as peptidyl aldehydes, epoxy succinate derivatives, etc., are poor in oral administration, tissue distribution, and cell membrane permeability, expectation has been toward the development of novel thiol protease inhibitors which can overcome these problems.